Androgen receptor identification in the diagnosis of eyelid sebaceous carcinomas

Adipophilin: roles in physiology and pathology

Adipophilin (ADRP/ADPH/PLIN2), an adipocyte differentiation-related protein, is highly expressed at a very early time during the differentiation of adipocytes. It assists in the formation and maintenance of intracellular lipid droplets and plays a role in regulating the physiological functions of the body. More and more studies indicate that it is involved in the occurrence and development of a variety of glycolipid metabolic diseases and tumours. In this review, we comprehensively stated the expression and functions of adipophilin and introduced its roles in physiology and pathology.

Clear cell variant of squamous cell carcinoma of eyelid, mimicking sebaceous carcinoma: A rare case report

Clear cell variant of squamous cell carcinoma (SCC) is an extremely rare neoplasm. Here, we report a case of clear cell variant of SCC which presented as an eyelid nodule. A 56-year-old male presented with a painless, small, pedunculated nodule in the left upper eyelid. On microscopic evaluation, tumor cells were arranged in nests and lobules with few foci of necrosis. Tumor cells were polygonal in shape, having abundant clear and vacuolated cytoplasm with peripherally pushed hyperchromatic nuclei. Two main differential diagnoses considered were sebaceous carcinoma and clear cell variant of SCC. On immunohistochemistry, tumors cells were negative for androgen receptor. A final diagnosis of clear cell variant of SCC was made. In a malignant eyelid tumor with clear cell morphology, a differential diagnosis of clear cell variant of SCC should be kept in mind before making a diagnosis of sebaceous carcinoma because sebaceous carcinoma possesses a poorer prognosis.

Ocular Adnexal Adenomatoid Sebaceous Gland Hyperplasia: A Clinical and Immunopathologic Analysis in Relation to the Muir-Torre Syndrome

The purpose of this study is to codify the microscopic diagnostic criteria for ocular adnexal brow and caruncular sebaceous gland hyperplasias (pseudoadenomatoid) that distinguish it from an adenoma. Clinical records and photographs were critically reviewed and microscopic slides were stained with hematoxylin and eosin and immunochemically stained for adipophilin, androgen receptor, p16, p53, a spectrum of cytokeratins, Ki-67 and mismatch repair nuclear protein expression for MLH1, MSH2, PMS2, and MSH6. The patients and their close relatives had no history of cancer. Cytokeratin 7 and especially cytokeratin 17 highlighted the presence of ducts in the hyperplastic lesion, which are not present in adenomas. p16 and p53 were negative and Ki-67 immunostaining demonstrated similar low proliferation indices for normal and hyperplastic glands. The mismatch repair nuclear protein expressions were preserved in both lesions. Histopathologic misdiagnosis of adenomatoid sebaceous gland hyperplasia as an adenoma can lead to the impression of an association with the Muir-Torre syndrome. Cytokeratins 7 and 17 immunostaining can be helpful in highlighting compressed ducts that in exuberant sebaceous gland hyperplasias may lead to a diagnosis of an adenoma (in which ducts are absent). Negative immunostaining for p16 rules out a possible etiologic role of human papillomavirus in hyperplasias and the negative p53 staining indicates the lesions are not truly neoplastic. The preservation of mismatch repair nuclear protein expression rules out the likelihood of the Muir-Torre syndrome. The current cases convincingly establish that sebaceous hyperplasia is not associated with the Muir-Torre syndrome by both clinical findings and immunohistochemical testing.Two yellow lesions, from the brow and caruncle, were examined microscopically and immunohistochemically to establish the diagnosis of sebaceous gland hyperplasia and to rule out the Muir-Torre syndrome.

Twenty-Eight Cases of Extraocular Sebaceous Carcinoma: A Correlative Clinicopathological and Immunohistochemical Analysis of Extraocular Sebaceous Carcinomas and Benign Sebaceous Gland Tumors

ABSTRACT

Extraocular sebaceous carcinoma (ESC) is a rare appendiceal skin tumor. In contrast to ocular sebaceous carcinoma, information about the exact cellular architecture of these lesions is scarce and the histogenesis of ESC is unknown. Here, we extend our previous study and investigate 28 extraocular carcinomas in comparison to 54 benign sebaceous tumors and 8 cases of normal sebaceous glands using a broad spectrum of antibodies against p63, several keratins, adipophilin, EMA, Ki67, androgen receptor, and mismatch repair proteins. This observational study demonstrates that p63- and K5/14-positive basaloid cells are key cells in normal sebaceous gland and in all sebaceous tumors and that these basaloid cells give rise to EMA+, adipophilin+ sebocytes, and K5/14+, K7±, K10± ductal structures. Finally, about half of ESC is associated with superficial in situ neoplasia, which provides evidence that at least part of these carcinomas arises from flat superficial in situ carcinoma. In contrast to the normal sebaceous gland, about half of all sebaceous tumors lack keratin K7. MMR protein IHC-profiles role will be discussed.

Androgen receptor expression in epidermal and adnexal tumours

INTRODUCTION

Androgen receptor (AR) immunohistochemistry is used in general pathology and in dermatopathology, particularly for sebaceous tumours. The goal of this study was to quantify AR expression in benign and malignant epidermal tumours and adnexal tumours.

METHODS

We studied AR expression in 301 skin lesions using standard immunohistochemistry and compared 10 trichoblastomas, 10 sebaceomas and 10 hidradenomas using 5 markers (cytokeratin 7 and 8, PHLDA1, BerEp4 and AR).

RESULTS

The rates of AR expression were: 22% in basal cell carcinomas, 3% in squamous cell carcinomas, 92% in sebaceous tumours, 10% in follicular tumours and 22% in sweat gland tumours. Benign sebaceous tumours were AR+ in 97% of cases. Only 12% of sebaceous carcinomas showed no AR staining. The immunohistochemical profiles of the comparative study were as follows: sebaceoma: AR+, CK7-, CK8-, PHLDA1-, BerEp4-; hidradenoma: AR-, CK7+, CK8+, PHLDA1+, BerEp4+; trichoblastoma: AR-, CK7-, CK8-, PHLDA1+, BerEp4+.

DISCUSSION

AR staining was positive in 92% of sebaceous tumours, including sebaceomas, in some cases indicative of Muir-Torre syndrome. AR staining is therefore highly sensitive for the diagnosis of sebaceous tumours, but it is non-specific and is best used in combination with other antibodies, notably anti-CK8 and PHLDA1, particularly to distinguish sebaceoma from hidradenoma or trichoblastoma.

Management of recurrent sebaceous gland carcinoma

OBJECTIVE

To evaluate the incidence and management of recurrent periocular sebaceous gland carcinoma at a tertiary ocular oncology service in the United Kingdom.

METHODS

This was a retrospective cohort study of 62 patients with sebaceous gland carcinoma treated between 2004 and 2017. A total of 10 eyes were treated for local recurrence. The following variables were recorded: age and sex of patient; tumour location, histological subtype; recurrence type; treatment and outcome.

RESULTS

Of the 62 cases with eyelid SGC, 10 (16%) had recurrences during the study period and satisfied inclusion criteria. There were six (60%) females and four males in the recurrent group. The mean time interval between initial excision and tumour recurrence was 37 months (median 23 months; range 4 to 84 months). Four patients received cryotherapy to the lids and conjunctiva to control recurrent disease and two patients were treated with topical or intralesional chemotherapy. Four patients (40%) underwent orbital exenteration during the study period. Metastasis occurred in 20% over a mean follow-up of 113 months (median 106; range 47-184 months).

CONCLUSIONS

The risk factors for local recurrence of SGC after wide excision with paraffin section control were reported, and an approach to these recurrent lesions was proposed. The results of this study will help guide surgeons dealing with the medical and surgical conundrum of recurrent disease. The risk of recurrence is highest in the first 2 years after initial excision.

Molecular profiling of a primary cutaneous signet-ring cell/histiocytoid carcinoma of the eyelid

Primary cutaneous signet-ring cell/histiocytoid carcinoma of the eyelid is a rare and aggressive neoplasm. Fewer than 50 cases have been reported in the literature, and the genetic driving mutations are unknown. Herein, we present a case of this rare disease along with the results of molecular profiling via targeted next-generation sequencing. The patient is an 85-year-old man who presented with left eyelid swelling initially thought to be a chalazion. After no response to incision and drainage and antibiotics, an incisional biopsy was performed. Histopathologic sections revealed a proliferation of cells with signet-ring and histiocytoid morphology arranged singly and in cords infiltrating the dermis, subcutaneous tissue, and muscle. The lesional cells strongly expressed cytoplasmic cytokeratin 7 and nuclear androgen receptor. Next-generation sequencing revealed a CDH1 mutation, which is known to confer signet-ring morphology in other carcinomas. Pathogenic mutations in NTRK3, CDKN1B, and PIK3CA were also detected. To our knowledge, this is the first documented genetic analysis of this rare disease with findings that offer insights into disease pathogenesis and potential therapeutic targets.

Villous Sebaceous Adenoma Arising from the Caruncular Surface Squamous Epithelium

A 68-year-old woman developed an asymptomatic left caruncular multilobular lesion over one year. Excision of the lesion displayed a benign sebaceous neoplasm taking origin from the surface squamous epithelium which invaginated into the stroma to create crypts resembling the conjunctival pseudoglands of Henle or the glands of Lieberkuhn of the small intestine. Scattered sebaceous cells were also discovered in the surface squamous epithelium. The cryptal walls spawned lateral sebaceous gland lobules that were adipophilin positive. p16 was positive in the surface epithelium, the cryptal walls, and in the basal cells of the sebaceous lobules. No defects in nuclear mismatch repair protein expression were identified, which together with the absence of a familial cancer history, rendered unlikely an association with the Muir-Torre syndrome.

Sebaceous carcinoma: evidence-based clinical practice guidelines

Sebaceous carcinoma usually occurs in adults older than 60 years, on the eyelid, head and neck, and trunk. In this Review, we present clinical care recommendations for sebaceous carcinoma, which were developed as a result of an expert panel evaluation of the findings of a systematic review. Key conclusions were drawn and recommendations made for diagnosis, first-line treatment, radiotherapy, and post-treatment care. For diagnosis, we concluded that deep biopsy is often required; furthermore, differential diagnoses that mimic the condition can be excluded with special histological stains. For treatment, the recommended first-line therapy is surgical removal, followed by margin assessment of the peripheral and deep tissue edges; conjunctival mapping biopsies can facilitate surgical planning. Radiotherapy can be considered for cases with nerve or lymph node involvement, and as the primary treatment in patients who are ineligible for surgery. Post-treatment clinical examination should occur every 6 months for at least 3 years. No specific systemic therapies for advanced disease can be recommended, but targeted therapies and immunotherapies are being developed.

The association between nuclear receptors and ocular diseases

Nuclear hormone receptors (NRs) are one of the most abundant transcription factors in the human cells. They regulate expression of genes via interactions with corresponding ligands, co-activators, and co-repressors. These molecular pathways play important roles in the development, cell differentiation, and physiologic and metabolic processes. Increasingly, targeting nuclear receptors is becoming a promising strategy for new drug development. The aim of this review is to discuss the association between nuclear receptors and eye development, and expand their role in various ocular diseases such as keratitis, cataract, glaucoma, uveitis, retinopathy, and ophthalmic tumors. Recent studies in this area are highlighted as well as future research directions and potential clinical applications. Finally, various strategies will be elucidated to inspire more targeted therapies for ocular diseases through the use of nuclear receptors.

Update on conjunctival pathology

Conjunctival biopsies constitute a fairly large number of cases in a typical busy ophthalmic pathology practice. They range from a single biopsy through multiple mapping biopsies to assess the extent of a particular pathological process. Like most anatomical sites, the conjunctiva is subject to a very wide range of pathological processes. This article will cover key, commonly encountered nonneoplastic and neoplastic entities. Where relevant, sections will include recommendations on how best to submit specimens to the ophthalmic pathology laboratory and the relevance of up-to-date molecular techniques.

Sebaceous gland carcinoma of the ocular adnexa - variability in clinical and histological appearance with analysis of immunohistochemical staining patterns

PURPOSE

The purpose of the study was to evaluate the characteristics of sebaceous gland carcinoma (SGC) of the ocular adnexae, which is due to a high variability in clinical, histological and immunohistochemical characteristics often challenging to diagnose.

METHODS

Records of six patients with SGC were reviewed, who underwent surgical excision and who were histologically diagnosed with SGC. For comparison, there were specimens from four patients with basal cell carcinoma (BCC) and four patients with squamous cell carcinoma (SCC). Histological and immunohistochemical analysis included stains for HE, cytokeratins (CKpan, Cam5.2), epithelial membrane antigen (EMA), androgen receptor (AR441), perforin and adipophilin.

RESULTS

SGC's were located in the upper (n = 2) or lower (n = 4) eyelid and were associated with various presenting clinical signs including chalazion-like lesions with pyogenic granuloma (n = 1), papillomatous conjunctival tumors (n = 3), a hyperkeratotic exophytic neoplasm (n = 1) and an ulcerating crusted lesion resembling chronic blepharitis (n = 1). The treatment was tumor resection, followed (if necessary) by adjuvant therapy with topical Mitomycin C (n = 2). Histologic characteristics included basophilic pleomorphic cells with vacuolated cytoplasm, prominent nucleoli, mitotic figures and in some cases pagetoid spread (n = 2). CKpan, EMA and Cam5.2 showed strong positive immunoreactivity in all specimens (SGC, BCC, SCC). Perforin immunostaining showed a varying, but overall weak, non-specific cytoplasmatic staining reaction in all lesions. AR441 positivity was noted with variable intensity in almost all lesions and in particular in pagetoid spread in contrast to non-tumor cells. Adipophilin showed an annular staining of lipid granules in immature sebaceous cells in SGC in contrast to a more granular staining pattern in BCC and SCC.

CONCLUSION

SGCs display a variety of clinical signs and may mimic many other lesions. Tumor resection, followed by histological and immunohistochemical analysis, leads to the diagnosis and initiation of the proper treatment regimen. Herein, immunohistochemistry showed an unequivocal profile in SGC and did not allow for an exact differentiation from BCC and SCC by immunohistochemical means only. An extended evaluation of HE stains remains essential. However, immunohistochemistry can make relevant contributions to the diagnosis of SGC, especially in cases of inconclusive histology, by positive staining for adipophilin in immature sebaceous cells or by AR441 labeling in cases of pagetoid spread.

p16 Expression Is Not a Surrogate Marker for High-Risk Human Papillomavirus Infection in Periocular Sebaceous Carcinoma

PURPOSE

To evaluate the role of high-risk human papillomavirus (HR-HPV) infection in periocular sebaceous carcinoma (SC) using multiple methods of detection, and to determine whether p16 overexpression is present and can be used as a surrogate marker for HR-HPV.

DESIGN

Retrospective observational case series with laboratory investigations.

METHODS

Unstained paraffin sections of 35 cases of periocular SC were analyzed with immunohistochemistry for p16 and subjected to polymerase chain reaction (PCR) for HR-HPV. A subset of 18 lesions that were p16-positive was further studied with a novel method of mRNA in situ hybridization (ISH) for the detection of transcriptionally active HR-HPV, an advanced technique with an enhanced sensitivity and specificity.

RESULTS

The clinical findings were in keeping with those of comparable earlier studies. Strong immunohistochemical p16 positivity (meeting the criterion of >70% nuclear and cytoplasmic staining) was present in 29 of 35 cases of periocular SC (82.9%). The selected 18 p16-positive cases tested were negative for HR-HPV using mRNA ISH. PCR yielded unequivocal results with adequate DNA isolated in 24 cases, 23 of which were negative for HR-HPV. One case was positive for HPV type 16, which was found to be a false positive as collaterally determined by mRNA ISH negativity.

CONCLUSION

No evidence was found for HR-HPV as an etiologic agent in the development of periocular SC using multiple modalities to maximize sensitivity and specificity and reduce the limitations of any single test. p16 overexpression is common in periocular SC but unrelated to HR-HPV status. Although p16 may be used as a surrogate marker for HR-HPV status in other tissue sites, this interpretation of p16 positivity is not applicable to periocular SC.

Updates on the Molecular Pathology of Selected Ocular and Ocular Adnexal Tumors: Potential Targets for Future Therapy

Ophthalmic pathologic studies of retinoblastoma first definitively elucidated a genetic etiology for cancer three decades ago. Advances in DNA sequencing, protein expression profiling, and the exploration of epigenetics have since led to categorization of tumors and clinical prognostication based on genetic aberrancy. There are now many neoplasms that are defined by a characteristic genetic signature. In the past several years alone, much has been discovered in regard to the original tumor-suppressor gene initially defined in retinoblastoma as well as in other intraocular tumors such as medulloepithelioma. Our further understanding of ocular adnexal tumors that result in substantial morbidity and mortality, such as sebaceous carcinoma, has also benefited from a genetic approach. In this article, we review the clinicopathologic features of the foregoing three entities--retinoblastoma, medulloepithelioma, and sebaceous carcinoma--in order to highlight discoveries in their underlying abnormal molecular genetic functioning.

Conjunctival Primary Acquired Melanosis: Is It Time for a New Terminology?

PURPOSE

To review the diagnostic categories of a group of conditions referred to as "primary acquired melanosis."

DESIGN

Literature review on the subject and proposal of an alternative diagnostic schema with histopathologic and immunohistochemical illustrations.

METHODS

Standard hematoxylin-eosin-stained sections and immunohistochemical stains for MART-1, HMB-45, microphthalmia-associated transcription factor (MiTF), and Ki-67 for calculating the proliferation index are illustrated.

RESULTS

"Melanosis" is an inadequate and misleading term because it does not distinguish between conjunctival intraepithelial melanin overproduction ("hyperpigmentation") and intraepithelial melanocytic proliferation. It is recommended that "intraepithelial melanocytic proliferation" be adopted for histopathologic diagnosis. Atypical proliferations are characterized either by bloated dendritic melanocytes with enlarged cell components (dendrites, cell bodies, and nuclei) or by epithelioid melanocytes without dendrites. Atypical polygonal or epithelioid pagetoid cells may reach higher levels of the epithelium beyond the basal layer. Immunohistochemistry defines the degree of melanocytic proliferation or the cellular shape (dendritic or nondendritic) (MART-1, HMB-45) or identifies the melanocytic nuclei (MiTF). Intraepithelial melanocytic proliferation without atypia represents increased numbers of normal-appearing dendritic melanocytes (hyperplasia or early neoplasia) that generally remain confined to the basal/basement membrane region. Intraepithelial nonproliferative melanocytic pigmentation signifies the usually small number of conjunctival basal dendritic melanocytes that synthesize increased amounts of melanin that is transferred to surrounding keratinocytes.

CONCLUSION

All pre- and postoperative biopsies of flat conjunctival melanocytic disorders should be evaluated immunohistochemically if there is any question regarding atypicality. This should lead to a clearer microscopic descriptive diagnosis that is predicated on an analysis of the participating cell types and their architectural patterns. This approach is conducive to a better appreciation of features indicating when to intervene therapeutically. An accurate early diagnosis should forestall unnecessary later surgery.

Sebaceous Carcinoma of the Ocular Region: The 2014 Professor Winifred Mao Lecture

Sebaceous carcinoma is a malignancy arising in the periocular region that can lead to blindness and tumor-related metastases. This study is a review of published literature and personal experience. This malignancy can arise from the sebaceous units in the tarsus (meibomian glands), in association with the cilia (Zeis glands), in the brow, and in the caruncle. There is a tendency for diffuse intraepithelial growth (pagetoid spread) that can be clinically invisible. Detection before lymph node metastasis is critical. This malignancy often masquerades as chronic unilateral conjunctivitis or blepharitis, typically in older patients. Management includes a 2-step approach with step 1 focused on eyelid and conjunctival map biopsies to determine the full extent of solid deep tumor and pagetoid spread. After complete review of all biopsies, step 2 is performed using local resection for all deep tumor, cryotherapy to pagetoid disease, and reconstruction. In most cases, the posterior lamella of eyelid is sacrificed with tumor removal, whereas the anterior lamella of the eyelid can be saved. After removal and cryotherapy, immediate reconstruction, using clean instruments, with buccal membrane graft for the posterior lamella and skin flap for the anterior lamella, is developed. For persistent or recurrent pagetoid disease, cryotherapy, topical mitomycin C, or plaque radiotherapy is provided. Exenteration is sometimes necessary. Sebaceous carcinoma, if detected early, can be managed with carefully planned map biopsy to determine tumor extent, followed by local resection, cryotherapy, and eyelid reconstruction. Orbital exenteration is occasionally necessary.

Demonstration of a Borst-Jadassohn-Like Phenomenon in Sebaceous Carcinoma of the Eyelid

A 77-year-old male presented with a diffuse, papular erythematous conjunctival mass that demonstrated on pathologic examination lobules of tumor in the conjunctival substantia propria and tarsus. The cells displayed numerous cytoplasmic vacuoles with extreme nuclear pleomorphism, consistent with sebaceous carcinoma. The overlying palpebral conjunctival epithelium exhibited regions of carcinoma in situ containing some vacuolated cells, alternating with a more classical appearance of pagetoid spread among normal surviving keratinocytes. Further analysis disclosed vesicular positivity for adipophilin and positive nuclear staining for androgen receptor. One tumor focus harbored exaggerated collections of intraepithelial tumor cells. These simulated the Borst-Jadassohn phenomenon of large nests of alien appearing cells normally encountered within the epidermis of the skin. This is the first description of this pattern created by an eyelid sebaceous carcinoma growing within the conjunctival epithelium.

Avoiding the major complication of ophthalmic pathology: misdiagnosis. A review of three common diagnostic challenges

Diagnostic errors in ophthalmic pathology are not uncommon. Pathology is a very subjective specialty with several biases dependent on such factors as training, experience, practice patterns, personal anecdotes, and inevitable human error. In addition to these factors, there are many cases where difficulty in diagnosis lies in differentiating between two very closely related, or similar appearing, entities that may have vastly different prognostic consequences. In this paper, we review three challenging areas wherein diagnostic dilemmas may occur. We outline some of the lessons we have learned in arriving at a correct diagnosis, which includes an admission of one's own limitations requiring consultation with other pathology subspecialists, and the use of immunohistochemistry.

Cytomorphology of sebaceous carcinoma with analysis of p40 antibody expression

BACKGROUND

Sebaceous carcinomas (SBCs) are aggressive tumors with the potential to cause great morbidity and mortality. Poorly-differentiated tumors may at times pose challenges for the correct diagnosis. p40, a new antibody that targets a short isoform of p63 has been shown as a promising squamous cell marker. In this study, we sought to evaluate cytomorphological features of SBC and p40 expression analysis.

METHODS

A total of 29 previously diagnosed cases of SBCs including fine-needle aspirates and histopathology specimens from various sites were reviewed and studied for p40 expression. p40 nuclear expression was semi-quantitatively assessed. Adequate positive and negative controls of non-small cell lung carcinoma were taken for comparison. Expression pattern of normal sebaceous glands was also analyzed.

RESULTS

Of the 29 cases, 13 (44.8%) were from the periocular region. The most common extraocular site was parotid gland. Morphologically tumors were categorized into well- and poorly-differentiated varieties based on extent of sebaceous differentiation. p40 positivity was seen in all cases of cytology aspirates and histology sections with similar intensity. No difference in percentage positivity of cells was recorded in well- and poorly-differentiated tumors.

CONCLUSION

p40 can be a valuable marker when evaluating tumors with possible sebaceous differentiation. Although p40 expression in SBCs is not as useful for the differential diagnosis that includes poorly-differentiated squamous cell carcinoma, this study, for the first time in the literature, highlights an important observation that p40 can be utilized as a marker for sebaceous lineage.

Morphological Spectrum of Orbitoocular Diseases in a Tertiary Health Centre in Keffi, North Central Nigeria

Aim. The aim of this study was to carry out a retrospective clinicopathological analysis of the ocular lesions requiring biopsy seen in the Department of Histopathology, Federal Medical Centre (FMC), Keffi, in North Central Nigeria. Materials and Method. A retrospective review of the clinicopathologic profile of orbitoocular lesions diagnosed at the FMC, Keffi, was done. Clinical and pathological data were obtained from the patients' clinical records and original biopsy reports, respectively. Results. Sixty-six cases of orbitoocular lesions were reviewed for this study. Of the 54 cases investigated, 28 were HIV negative while 26 were HIV positive (37.1% of all cases). There were 30 cases of Ocular Surface Squamous Neoplasia (OSSN) with a male-to-female ratio of 0.9 : 1. Squamous cell carcinoma (SCC) was the most frequent OSSN with 17 cases. The mean age of cases of SCC is 37.1 ± 7.6 SD (years). The mean age of carcinoma in situ is 35.8 ± 11.4 years. Conclusion. There was no significant difference in the sex distribution of patients with OSSN. It is probable that a diagnosis of squamous cell carcinoma may be encountered in about a year after diagnosis of a carcinoma in situ especially if the in situ carcinoma is left untreated or improperly treated.

[Differential diagnostics of sebaceous tumors]

Sebaceous tumors are epithelial tumors with a differentiation towards sebaceous adnexal structures of the skin. They imitate the epithelial cells of mature sebaceous glands, sebaceous ducts, immature (embryonic) sebaceous structures or sebaceous glands that are not stimulated by hormones (mantle structures). This article explains the classification of sebaceous tumors on the basis of the normal histology of sebaceous glands. Clinical and histopathological criteria are given for the most important sebaceous tumors. The differential diagnosis of sebaceoma, sebaceous adenoma and various types of sebaceous carcinoma is emphasized. The importance of a specific diagnosis of adnexal tumors is demonstrated by tumor-associated syndromes with involvement of other organs (e.g., Muir-Torre syndrome and Birt-Hogg-Dubé syndrome). Furthermore, conceptional controversies, problems in differential diagnosis and the impact of immunohistochemical staining in the assessment of sebaceous tumors are considered.

Papillary hidradenoma of the eyelid margin: clinical and immunohistochemical observations further supporting an apocrine rather than an eccrine origin

A 46-year-old woman was evaluated for a "recurring papilloma" of the left medial upper eyelid margin. Beneath the papillary lesion medial to the punctum was a 5-mm diameter cutaneous mass thought to be cystic. After excisional biopsy, histopathologic analysis documented the presence of an epidermal keratinizing squamous papilloma surmounting a circumscribed dermal papillary hidradenoma composed of deeply eosinophilic columnar cells. Additionally, there was intraductal proliferation of tumor extending toward a subclinical poral opening through the epidermis. Immunohistochemistry proved the apocrine nature of the benign, non-cystic lesion by virtue of its nuclear androgen receptor and cytoplasmic gross-cystic disease fluid protein-15 positivity, along with its smooth muscle actin-positive myoepithelial layer. This and prior cases establish that apocrine tumors, both benign and malignant, are strictly localized at or near the eyelid margin where only apocrine glands are found. These tumors are more often papillary than solid adenomas, and most exceptionally can be malignant. We review the differential diagnosis of simulating eccrine eyelid tumors. We recommend wide local excision for benign lesions, in view of possible intraductal extension that can be eccentric to the main tumor and the miniscule potential for malignant transformation.